Case shift mechanism for typewriting machines



ly 1940- H. A. AVERY ET AL ,016

CASE SHIFT MECHANISM FOR TYPEWRITING MACHINES FiledFeb. s, 1939 2 Sheets-Sheet 1 Ey/TORS lNV 17m lam/er & 3 J02) Zia/Argo Anonu f July 1940- H. AVERY El AL 2,206,016

CASE SHIFT MECHANISM FOR TYPEWRITING IIACKINES Filed Feb. :5. 19:9 z-sheats-sneeflz INVENTORS flcw y JAM/{ref BY 0// 'kgun Patented July 2, 1940 CASE SHIFT IVECHANISM FOR TYPE- WRITHNG MACHINES Henry Allen Avery and Joseph P. Barkdoll, Groton, N. Y., assignors to L. C. Smith & CoronaTypewriters, Inc., Syracuse, N. Y., a corporation of New York Application February 3, 1939, Serial No. 254,362

'7 Claims.

The invention relates to improvements in caseshift mechanisms for typewriting machines and its principal purposes are to provide a simple, inexpensive and effective construction whereby case change may be .efiected in such machines; provide a simple, light, compact and sturdy construction whereby case change by shifting the platen carriage may be effected and which is especially suitable for small and light portable typewriting machines of the semi-front-strike variety; provide an improved carriage shift frame and adjustable mounting therefor; and to provide improved means for actuating and determining the shift limits of a case-shift frame.

To the foregoing and other ends which will hereinafter appear, the invention consists in combinations of devices, arrangements of parts, and features of construction which will be described hereinafter and particularly pointed out in the appended claims.- In the drawings, in which the invention is illustrated in a preferred form embodied in a small,

flat, portable typewriting machine of the semivided along'their lower edges with horizontal infront strike or three-quarter strike variety,

Fig. 1 is a vertical, medial, longitudinal sectional view of the machine on the line I-I of Fig. 2; Fig. 2 is a detail vertical, transverse sectional view taken on the lineZ-Z of Fig. l and showing certain only of the parts illustrated in Fig. 1;

30 Fig. 3 is a detail View showing in side elevation parts of the main and case-shift frames of the machine as viewed from the left-hand side of the machine;

. Fig. 4 is a. detail sectional view taken onthe line 4-4 of Fig. 1; I

Fig. 5 is a fragmentary top plan view of the machine showing the forward portion of the machine;

Fig. 6 is a fragmentary bottom plan view showing the rear portion of the machine;

Fig. 7 'isa detail rear elevation of the machine showing'parts of the machine; and

Figs. 8 and 9 are detail sectional views on an enlarged scale taken on line P-P of Fig. 3 and illustrating the two pivotal connections between the main and case-shift frames of the machine.

The invention is shown embodied in a very small and fiat portable typewriting machine of very light weight, the machine being drawn to 50 full scale in Figs. 1 to '7. Only so much of said machine as is necessary to a full understanding of the present invention is shown and will be hereinafter specifically described. H

The main frame of the machine comprises a side walls or plates Ill, and an upstanding sheet" metal partition plate or cross-wall I I. The cross.-

wall inclines upward and rearward at an angle .of

forty (40) degrees to the horizontal and is pro,- vided along its lower edge with an integral horizontal forwardly extendingflange II located closely adjacent the bottom edges of the side walls Ill. The side walls I9 are greatly reduced in height at their rear ends for about one-quarter of their length, and cross-wall II connects the rear ends of the higher portions of the side wallsimmediately forward of said reduced rear end portions of the side walls. Wall II extends upward about one-half the maximum height of the side walls I0. Wall II is formed at each end witlra pair of lugs I2, and flange II- on said walliis" formed at each end with a lug I2 which lugs-i2 and I2 extend outward through apertures inthe adjacent side wall I0 and are headed over againstwardly projecting stiffening flanges Ill extending from their front ends substantially to flange.

II of wall II. Walls =IIJ are provided along their lower edges in rear of flanges II) with horizontal inwardly projecting stiffening flanges Ill which flanges I-Il extend to the rear ends of said walls I0 and preferably increase in width toward their- .front ends, as shown. Each flange Ill has a slightly upwardly offset forward end portion abutting flatwise the bottom face of flange H I and spot-welded to said flange II at points I3.

The case-shift frame of the machine comprises a sheet metal carriage bed and three sheet metal brackets detachably but rigidly held'to the bed. The carriage bed I4 is formed along its longitudinal edges with integral upstanding raceway flanges M bracket I5 .located'substantially midway the ends of the bed and substantially medially of the sides of the machine,-and the other two-of said brackets are a pair of brackets i6 located adjacent opposite ends of the bed-and adjacent opposite sides of the machine." Bracket I 5 is rigidly but detach- One of said three brackets is a" to the carriage bed at the under-faceof the :bed

register through axially aligned threaded apertures 2| and 22 formed in the respective side walls IQ of the main frame adjacent the upper rear corners of said side walls. Pintle screw 19 is adjustably threaded through aperture 21 in the left-hand side wall of the main frame, and pintle screw 20 is adjustably threaded through aperture 22 in the right-hand side wall of the main frame, the outer end of each screw being slotted to receive a screwdriver. Lock nuts 23, threaded on the outer ends of the pintle screws against the outer faces of the side walls ll] of the main frame, serve to releasably lock the pintle screws in adjusted position against accidental turning.

Each bracket member N3 of the shift frame is formed with an integral pendent pivot ear 15 disposed flatwise in a vertical plane extending fore and aft of the machine, the two pivot ears being located inside the side walls I adjacent opposite sides of the machine and spaced apart sufficiently less than said side walls to permit of adjustment of the shift frame transversely of the machine. Ear I6 of the right-hand one of the brackets I6 is provided with a screwthreaded cylindrical bearing aperture 25 through which is screwed the pintle screw 20, and ear 16 of the left-hand bracket 16 is provided with a non-threaded cylindrical bearing aperture 24 axially aligned with aperture 25 and through which extends an elongated reduced nonthreaded inner pintle end portion l9 of pintle screw IS. The several screw threads are of fine pitch, and ear H of left-hand bracket I6 is slidable on pintle portion |9 longitudinally of the latter.

A sheet metal bracket 26, located medially of the sides of the machine behind cross-wall ll of the main frame, is detachably but rigidly held to the wall II at therear face of said wall by screws 21 and is provided with two superposed, vertically spaced, rearwardly extending lugs 28 and 29. Shift frame bracket member l5 has a narrow forward integral end portion l5 which is located medially of the sides of the machine and extends between, and is movable up and down between, lugs 28 and 29 on bracket 26.

End portion l5 of shift frame member I5 is normally seated on the upper end of an adjustable stop screw 30 threaded upward through the lower lug 29 on bracket 26, such seating determining the lower-case printing position of the shift frame. Rocking of the shift frame from lower-case printing position is limited, to arrest the shift frame in upper-case printing position, by means of an adjustable stop screw 3| threaded upward through portion I5 of shift frame member I5 for engagement of the upper end of screw 3| with the under face of the upper stop lug 28 on bracket 26 upon upward swinging of member 15. Screws 30 and 3| are located one be hind the other medially of the sides of the machine with their slotted heads at the lower ends of the screws and accessible from the bottom of the main frame for adjustment of the screws. Suitable lock nuts 32 (Fig. 1) are preferably threaded on the screws 30 and 3| so as to be accessible from the bottom of the main frame, as shown.

The shift frame member I5 is bent, forwardly of the carriage bed and about midway the front and rear ends of said member, along a line extending transversely of the machine in such manner, as to support the carriage bed with the plane of its bottom face substantially parallel to the plane of the main frame cross-wall II, with the raceway flanges I4 of the carriage bed extending generally upward and forward from the bottom of the bed and with the forward 5 part of said member I5 extending substantially horizontally forward from said line of bend, all as shown more particularly in Fig. 1, when said member [5 is seated at its front end on stop screw 30 in the lower-case printing position of the shift frame.

A suitable platen carriage 33, having the usual roller platen 34 journalled therein in the usual manner, is supported by the forwardly and downwardly tilted bed 44 to travel transversely of the machine over the low rear part of the main frame, the tilted bed supporting the carriage in correspondingly forwardly and downwardly tilted relation to the main frame with the platen above and forward of the pivotal axis of the shift frame and above the low rear part of the main frame. The carriage is provided with suitable raceway flanges 33 opposed to raceway flanges 14 of bed 14 and travels, as is common in the art and as indicated, in Figs. 1 and 3, on suitable ball bearings 35.

The machine is provided with the ordinary arcuate type bar segment 36 in the usual slots of which on the usual arcuate pivot wire 31 carried by the segment are pivoted the type bars of the usual set of type bars each carrying the usual two types. One central type bar and one side type bar are shown, said type bars being designated by the reference numeral 38, and each type bar carrying a lower-case type 39 and an upper-case type 40, the segment supporting the type bars as usual to print at a common printing point medially of the sides of the machine. In the machine shown, the segment is secured by screws 4| to the front face of cross- 0 wall ll of the main frame medially of the sides of the machine, for striking of the type bars to a printing point which is located as is indicated in Fig. 1, and as is common in machines of the semi-front-strike or three-quarter-strike 1 variety, on the upper front portion or quarter of the platen. The pivot wire 3'! in the upwardly and rearwardly inclined segment 36 lies in a plane parallel to that of wall II. The,;;; type bars normally extend upward and forward from their pivots and are normally supported adjacent their type-carrying ends by a type bar rest 42. Rest 42 extends across the main frame about mid-length of the machine and at the top of the main frame and is secured at its ends to side walls ll] of the main frame by screws 43. Any suitable means may be employed for actuating the type bars.

The shift frame and the platen carriage with its platen are constantly biased by reason of m tionally operable shift key levers of bellcrank form each having a forwardly extending arm 44 and a pendent downwardly and rearwardly extending arm 45, the forwardly extending arm 44 of each said key lever extending forward beyond the front end of the main frame and carrying'a shift key 46 at the forward end of said arm 44. Extending between the upper portions of the main frame side walls forward of the type bars is a metal fulcrum bar 41. V Said bar extends horizontally transversely of the machine with'its ends abutting the inner faces of walls 10 and is rigidly but detachably held to said walls by screws 48. Adjacent each end thereof fulcrum bar- 41 is provided with a slot 49, said two slots 49 lying in parallel vertical planes which extend fore and aft of the machine. Extending longitudinally through said bar horizontally and transversely of the machine are two straight and parallel pivot or fulcrum wires 50 and 5|. The wire 50 crosses both slots 49 adjacent the upper ends of the slots, and wire 5| crosses both slots 49 adjacent the lower ends of the slots.

The two shift key levers are formed of sheet metal and pivotally momited on the higher wire 55 with each lever engaged in and guided by a different one of said slots 49. Two fore and aft extending bellcrank sub-levers located between walls Ml adjacent opposite sides of the machine and formed of sheet metal are pivotally mounted on the lower wire 5! with each said sub-lever engaged in and guided by a different one of said slots 45 in fulcrum bar 41. Each fore and aft extending sub-lever has an upwardly and forwardly extending front arm 52 and a rearwardlyextending arm 53i Lever arms 53 extend through and are movable up and down in slots 54 in cross-wall H of the main frame, each said lever arm being formed behind said wall with a forked rear end port ion'53 in which is engaged the outer end of the outer arm of one of a pair of sheet metal sub-levers 55 of the first order which extend transversely of the machine behind wall l Each sub-lever 55 is engaged at its inner end under the forward end portion of shift frame member l5 substantially at the medial fore and aft center line of the machine and is fulcrumed intermediate its ends on one of two horizontal pivot screws 56 extending fore and 'aft of the machine and held to lugs 51 formed integrally with wall ll.

Extending horizontally and transversely of the machine between walls l0, adjacent the tops of.

said Walls and forward of fulcrum bar 41, is a return stop device 58 for the shift key levers, said device extending over the key-carrying arms 44 of the shift key levers and being rigidly but detachably held to walls ill by screws 59. Each key lever and its associated fore and aft extending sub-lever are connected by a coiled return spring 55 of the tension pull type, the spring being connected at its ends to said levers to the rear of the lever fulcrums to maintain arm 52 constantly engaged behind arm 45 and to normally urge the connected key lever, fore-and-aftextending sub-lever, arid transversely extending sub-lever into the relative positions thereof shown in the drawings. In this normal positional arrangement of the connected levers, the arms 44 of the shift key levers are urged upward against the under side of stop 53, and the inner ends of levers 55 are lowered far enough for part 55* of shift frame member I5 to seat on top of stop screw 35.

By depressing either shift key 46 the shift frame may be rocked upward and rearward until stop screw 3! engages under stop 28 to thereby position platen 34 in the upper-case printing position of the latter indicated in dotted lines in Fig. 1. Each wall I!) of the main frame is formed at its front end with an upstanding lug 6| extending inward from said wall transversely of the machine and provided with a vertical guide slot 52 for the forward arm 44 of the adjacent shift key lever. Slot B2 in each lug Si is widened in thelower portionthereof at one side thereof to provide a downwardly facing stop or looking shoulder 63. Arm 44 of each key lever is sufficiently flexible laterally to permit engagement thereof under the associated stop shoulder53 after full depression of said key lever, to thereby #110 permit locking of the shift frame in upper-case position when desired. It will be observed that an extremely light, compact and inexpensive construction is provided in which, nevertheless, a predetermined working (m5 relation will be maintained between the main and shift frames and between the platen carriage shift frame and the type bar segment. It will also be observed that both frames are of simple, light and inexpensive construction; that the in shift frame may be readily assembled on and removed from the-main ,frame; and that the key-actuated means for rocking the shift frame is so associated with said frame that said frame is rockable by power applied midway its ends,

What we claim is:

1. In a typewriting machine, the combination of a main frame, a case shift frame, means comprising two threaded members screw-.thread-coupling the shift frame with the main frame for 30 case changing movement of theshift frame relatively to the main frame about a horizontal axis extending transversely of the main frame by rocking of the shift frame and turning of one of said threaded members of said coupling on the other 5.35 threaded member of said coupling, means spaced along said horizontal axis from said first-mentioned coupling means and coupling the shift frame with the main frame for transverse movement of the shift frame relatively to the main frame along the said horizontal axis as well as for pivotal movement of the shift frame relatively to the main frame about said horizontal axis under control of said first-mentioned coupling means, and means for rocking the shift frame about said axis to change the printing case determining position of said shift frame.

2. In a typewriting machine, the combination of a main frame, a case shift frame, means connecting the frames for pivotal and sliding movements of the shift frame relatively'to the main frame respectively'about and along a horizontal axis extending transversely of the main frame, a member having a fine pitch screw thread connection with one of said frames, the axis of which screw thread connection is coincident with said horizontal axis, means for locking said member to the other one of said frames, and means for rocking said shift frame on the fine pitch screw thread and about said coincident axes for case 60 changing with said member locked to said other one of said frames.

3. In a typewriting machine, the combination of a main frame, a case shift frame, a screw extending horizontally transversely of the main frame and in threaded engagement with one of said frames, means for locking saidscrew to the other one of said frames, means for rocking the shift frame on the screw threaded engagement between the said screw and one of said frames and about the axis of said screw for case changing with said screw looked as specified, and means constantly connecting the frames for pivotal and sliding movements of the shift frame relatively to the main frame respectively about and along an axis coincident with the axis of the screw.

4. In a typewriting machine, the combination of a main frame, a case shift frame, a pintle screw having a fine pitch thread extending horizontally transversely of the main frame adjacent one side of the main frame and screw thread coupled with both frames, means for releasably locking said pintle screw to one of said frames, means for rocking the shift frame about the axis of said pintle screw for case changing while the said screw is so locked, and means connecting the shift frame with the main frame adjacent the opposite side of said main frame from said pintle screw for pivotal and sliding movements of the shift frame relatively to the main frame respectively about and along an axis coincident with the axis of said pintle screw.

5. A typewriting machine having, in combination, a main frame, a pair of axially aligned and axially spaced pintles extending horizontally inwardly transversely of the machine and each adjustably screw threaded through a part of said main frame, means for releasably locking each pintle to the main frame in adjusted position against accidental turning relatively to the main frame, a case shift frame screw thread coupled to one pintle and coupled to the other pintle to rotate about and slide along the latter, and means for rocking the shift frame on the locked pintles for effecting printing case change.

6. A typing machine having, in combination, a main frame, a sheet metal case shift frame, means adjacent one side of said main frame screwthread-coupling the shift frame with the main frame for rocking movement relatively to the main frame on the screw thread of said screw thread coupling and about and along a horizontal axis extending transversely of the machine, means adjacent the opposite side of the main frame coupling the shift frame with the main frame for turning and sliding of the shift frame about and along said axis, means for rocking the shift frame about said axis for case changing, and case shift stop means located substantially medially of the sides of the main frame for limiting the arc of rocking movement of the shift frame about said axis.

7. A typewriting machine having in combination, a main frame, a pair of axially aligned and axially spaced pintles extending horizontally inwardly transversely of the machine and each adjustably screw threaded through a part of said main frame, one of said pintles having an unthreaded inner end, means for releasably locking.

-threaded inner end of the other pintle to rock about and move axially along the latter, and

means for rocking the shift frame about the axes of the locked pintles for effecting printing case change.

HENRY ALLEN AVERY. JOSEPH P. BARKDOLL. 

